Conveyer-belt tightener for harvesters.



No. 832,361. PATENTED OCT. 2, 1906. L. B. BLEVINS. CONVEYER BELT TIGHTENER FOR HARVESTERS.

APPLIOATION FILED DBO. 20. 1905.

` /5 ,Z5 lll 7 i v u /5 UNITED sTATEs PATENT oEEioE.

LEVI By. BLEVINS, F DESLACS, NORTH DAKOTA.

CONVEYER-BELT TIGHTENER FOR HARVESTERS- Specification of Letters Patent.

Patented Oct. 2, 1906.

4Application filed December 20,1905. Serial No. 292,546-

tighteners for harvesters, or, in other words,

y with paw to mechanism for maintaining a proper tension upon the canvas or conveyer belts which form a part of the mechanism of harvesting-machines.

The invention has for its object to provide a simple and efficient mechanism whereby the desired tensioning may be readily effected, the construction being such as to require a minimum of power to provide the necessary tension, and also such as to maintain itself in ad'usted position, dispensing entirely is and ratchets or other retaining or lockin mechanism.l y

To t ese ends my invention consists in certain novel features, which I will now roceed to describe' and will then particular y point out in the claim.

In the accompanying drawings, Figure 1 is a planvview of a structure embodying my invention in one form, the conveyer-belt or canvas being partly broken away to show the underlying construction. Fig. 2 is an enlarged detail sectional view taken through one side of one end of Fig. 1 in a plane parallel with the conveyer-belt. Fig. 3 is a detail view taken in section upon the line of Fig. 2 and looking in the direction of the arrows, and Fig. 4 1s a similar view taken on the line y y of Fig. 2 and looking in the diiection of the arrows.

In the said drawings, 1 indicates the parallel frame-bars which support the conveyerbelt 2. This latter passes around a drivingroller 3, mounted in one end of the bars 1, and also around an idle roller 4, supported at the other end of the frame-bars by the adjustinfr mechanism which I have devised. The roller 4 is mounted on a shaft 5, which has its bearing in sleeves 6, carried by slide-bars 7. Each slide-bar 7 is mounted to slide longitudinally of the corresponding frame-bar 1 in a suitable uideway 8, secured to the inner face of said ame-bar, whichis recessed or cut away, as indicated at 9, to receive said guideway. Each guideway is 'Apreferably the inner face of the frame-bar by bolts or rivets 10, which pass through the frame-bar and also through the external steel plate 11, with which the frame-bar is reinforced on its outer side. The margins of the bar or plate from which the guideway is formed are first bent outward parallel with each other, as indicated at 12, and then inward toward each other, as indicated at 1 3, leaving between their rejection or nut hereinafter referred to. here is thus formed an internal recess or Away 15, in which the bod of the slide-bar 7 fits and slides. Each slidearisprovided with a nut or threaded projection 16, connected thereto in any suitable way-as, for instance,

intothe body of the bar, as shown in Fig. 2. This nut or threaded portion extends out through the slot 14, which is formed to accommodate-it, and its rojecting portion is provided with a threa ed aperture 18. screw-shaft 19 fits this threaded aperture, said screw-shaft being mounted to revolve without moving longitudinally in bearings 20, carried by brackets 21, mounted on the guideway 8 near each end thereof. These earing-brackets straddle the slot 14 and are rovided with lugs 22 on each side thereof, t ough which they are secured to the top flanges 13 of the guideway 8 by means of bolts 23.

The construction just described is duplicated on the inner face of each of the framebars 1, and there is mounted in said framebars a transverse shaft 24, provided with a removable crank-handle 25, by means of which it may be readily rotated. The shaft 24 has mounted thereon near each framebar a bevel-gear 26, and each screw-shaft 19 is provided at one end with a bevel-gear 27, meshing with the corresponding bevel-gear 26 on the operating-shaft 24.

It will be seen that when the canvas or conveyer-belt has become slack and requires tensionin the crank-handle 25 may be applied to t e operating-shaft 24 and said operating-shaft may be therebyrotated. Such -rotation will be transmitted simultaneously through the bevelears 26 and 27 to bot screw-shafts 19, an these latter by their engagement with the nuts or threaded projections 16 on the slide-bars 7 will move these latter -simultaneously outward, increasing the distance between the bearings 6 of the by having its threaded lower end 17 screwed formedioffa sheet or bar of metal, secured t0 edges a slot 14 for the passage of the threaded ,l

Ilo

roller 4 and the roller 3 at the other end of the frame-bars, thereby taking up the slack of the belt and giving: to it the desired tension. 1t will be readily understood that by reason of the employlnent of 'the screwshafts for ell'ecting th-is moven'ient an elli. cient vtension may be obtained by the application of a' relatively small amount of power to the operatilig-shaft. It will also he seen that the parts will= remain in any position to which they may be auljusted, so that l am enabled to dispense with the ratclwt-wheels and retaining-pawls or other retaining or locking devices usually em )loyed in mechanism ol'l this description. 11]' the tension is too great, it may readily he relieved by rotating the operating-shaft in the op osito direction, and 1n either case all that 1s required is to apply the crank-handle and turn the o erats ing-shaft in the proper direction to t 1e desired extent.

Havine thus'fully described my invention, what 1 e aim ns new, and desire to secure by Letters Patent, is-

In a mechanism of the character described, the combination, with arallel fra1nebars, and an idle relier, of gui( eways seated on the inner faces of the l'ralne-lmrs and having lon gitudinal T-shaped slots therein, slide-bars litting in said guideways and having threaded apertures ftherein, bearings l'or the idle roller on the projecting ends ol' said slidebars, )rejections having threaded portions extem ing through the slots ol" the guideways and engagingy said threaded a iertures threadml apertures in the outer en( s el saitv pre"eetions, bearing-brackets mounted on said guideways near the ends there-ol" and eX- tending' across the slots therein, screw-shafts mounted in said l)caring-brackets engaging the threaded apertures ol' the slide-bar projections and havin;r bevel-gears on their extremities, an operatilig-shalt n'iounted inthe frame-bars provided with bevel-gears to mesh withy the bevel-gears of the screw-shalt, and means for operating said shalt, substantially as described.

.ln testimony whereof I allix my signature in presence of two witnesses.

LEVI B. BLEVINS. 

